Electric bell



(No Model.)

J. T OBRIEN.

ELECTRIC BELL.

Patented July 27,1897. Fz/gl.

Ifllliilb lllllllll= INVENTOR V UNITED STATES PATENT OFFICE.

JOHN T. OBRIEN, OF' BRIDGEPORT, CONNECTICUT.

ELECTRIC BELL.

SPECIFICATION forming part of Letters Patent No. 587,062, dated July 27,1897.

Application filed April 13 1897.

To all 10700711 it may concern.-

Be it known that 1, JOHN T. OBRIEN, 5min zen of the United States,residing at Bridgeport, in the county of Fair-field and State ofConnecticut, have invented certain new and useful Improvements inElectric Bells; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention has for its object to provide an electric bell soconstructed that when placed in series all the bells in the series maybe rung simultaneously, and should anything interfere with the ringingof any of the bells no other bell in the series will be affected Itherebyas,for example, should dirt accum ulate between the contacts theclosing of the main circuit,'while it will not produce continuousringing of this special bell, will cause a single blow to be struck andwill thereby give a warning, no other bell in the circuit being in anyway affected by the condition of the special bell which is not workingperfectly. In order to accomplish this result, I have devised the novelelectric bell of which the following description, in connection with theaccompanying drawings,is a specification, reference-characters beingused to designate the several parts.

In my novel bell there is no closing and opening of the main circuit tocause the ring-. ing of the bell, but instead of a closing and openingof the main circuit to ring the bell this result is accomplished by theclosing and opening of a shunt-circuit.

Figure 1 is a diagrammatic view illustrat ing a number of my novelelectric bells in a circuit, and Fig. 2 is an enlarged-view of one ofthe bells.

1 indicates the bells; 2, strikers; 3, electromagnets; 4, armatures bywhich the strikers are carried; 5, a battery or other source ofelectrical energy; 6, a switch a, the main circuit; 19, shunt-circuits,and 7 binding-posts. The armature is shown as pivoted on a post 8 and ascontrolled by a spring 9.

10 denotes a post having an opening in which a pin 11 is adapted toslide, said pin being locked in place after adjustment by a screw 12.The tip of this pin is provided Serial No. 631,930. (No model.)

with a block of insulating material, as at 13, and with a contact 14,which lhave shown as substantially U- shaped, the free end of thiscontact lying at a slight distance from the insulating material.

15 is a contact preferably a spring extending from the armature and thefree end thereof lying between the insulating material and the free endof contact 14, said contact 15 lying normally in contact with theinsulating material, as clearly shown in Fig. 2. The shape of contact 14is of course not of the essence of my invention. It it simply necessarythat contact 14 extend away from pin 11 back of the insulating materialand be so shaped that the free end thereof may be readily engaged bycontact 15. Should any adjustment of contact 15 be necessary to make thebell ring softer or louder, it may be readily eifected by looseningscrew 12 and moving pin 11, which carries contact 14 in or out, and thenlocking it in position after adjustment.

The operation will be readily understood from Fig. 2, which see inconnection with the diagrammatic figure.

When the main circuit is closed, the current is through theelectromagnet, and the armature is drawn to the poles, causing a blow ofthe striker upon the bell. The movement of the armature into contactwith the poles of the magnet carries contact 15 away from theinsulating-block and into engagement with contact 14, which closes theshunt circuit 1). The current now passes through the shunt-circuitinstead of through the magnet and passes back into the main circuitagain, as at 16. The instant the shunt-circuit is closed the armaturedrops away from the poles of the magnet and contact 15passes out ofengagement with contact 14 and rests against the block of insulatingmaterial, as in the drawings, which opens the shunt-circuit and againcloses the main circuit, thereby causing another blow upon the bell.This shifting of the current from the main circuit slightest extent bybells not in operative condition, which will themselves ordinarily soundonce each time the main circuit is closed.

Having thus described my invention, I claim 1. The combination with amain circuit, a shunt-circuit, a bell and an electromagnet in the maincircuit, of an armature in the shuntcircuit carrying a striker and acontact 15, and a pin 11 in the shunt-circuit carrying aninsulatingbloek and a contact 14, said contact 15 being normally incontact with the insulating-block but being placed in engagement withcontact 11 and thereby closing the shunt-circuit by the movement of thearmature to the magnet which is caused by the closing of the maincircuit.

2. In combination a main circuit, a shuntcircuit, a bell, anelectromagnet in the maincircuit, an armature in the shunt-circuitcarrying a striker and a contact 15 and an adjustable pin 11 in the shlint-circuit carrying an insulating-block and a contact 11, said contact15 being normally in contact with the insulating-block but being placedin engagement with contact 14 and thereby closing the shunt-circuit bythe movement of the armature to the magnet which is caused by theclosing of the main circuit.

3. The combination with a main circuit, a shunt-circuit, a bell and anelectromagnet in the main circuit, of an armature in the shunt-circuitwhich carries a striker, an adjustable pin in the shunt-circuit whichcarries an insulating-block and a U-shaped contact 14, and a contact 15on the armature the free end of which normally engages theinsulatingbloek and is adapted to be placed in engagement with contact14 by the movement of the armature to the magnet when the main circuitis closed.

In testimony whereof I aflix my signature in presence of two witnesses.

JOHN T. OBRIEN.

Witnesses:

A. M. WoosTER, SUSAN V. IIELEY.

